I was considering booking a transatlantic flight last Saturday (for travel in July) at about $650. I decided to sleep on it to make sure I was happy with my itinerary, scheduling conference, library research, in the right proportions. The next morning, all flights were over $1100. Less than 8 hours later! They are still all over $1000.
Don't despair. I managed to get my $367 flight for $464. (And I'm sounding grateful about this?!) Hopefully yours will start sliding. It's just insane.